I have a table like this:

I would like to delete all records where event = 'repo', but after event = 'harv'.

I mean the expected result:

Do you know how to do it the easiest way?

CodePudding user response：

Use Series.cummax for match all next rows after matching harv and chain by & for bitwise AND or | for bitwise OR with mask for compare for equal or not equal repo:

df = df[~(df['event'].eq('harv').cummax() & df['event'].eq('repo'))]
#alternative
#df = df[~df['event'].eq('harv').cummax() | df['event'].ne('repo')]
print (df)
   event   value
0   seed    57.0
1    ghy   869.0
2   repo  5324.0
3   repo     NaN
4   repo     NaN
5  trans    32.0
6   harv    12.0
7   weig  6995.0